Hunton/ilmor Build - Page 21

baj666 · 05-12-2010, 05:58 PM

another fine post mate

..watch your hair dont get caught up in the drill Peter

Tony Davis · 05-12-2010, 07:19 PM

Hey Pete, I'm curious as to the thinking behind the engine mounts, did you have second thoughts about going purely CF, or were they more for bling purposes and you'd planned to double them up with Ally?

peterunwin · 05-12-2010, 07:31 PM

Quote:

Originally Posted by larby

Lovely work as usual Peter!

It's interesting to see how you are mounting the engines. My revenger had great big cradles almost the length of the engine bay made from 6mm steel that the motor sat on.
I was going to make a similar set for the new build, but from Stainless or ally, which actually went the whole way and braced to the transom and bulkhead too. I always wondered how engines mounted on little bits of angle ally at one point on the stringer didn't just rip out under offshore use!
What would be your thoughts on this, bearing in mind the work done to my hull? Am I going OTT? If so, do I just need two little bits of angle, or somewhere in between?

Cheers, James

Hi James,
Thanks

The engine bearers in the Hunton were installed prior to making the engine choice so are strong enough for a pair of big diesels therefore i don't need to spread the load over a large area, also by using carbon fibre for the angles the bonding is so good to the longitudinals that it would cause delamination of the fibres to remove them. The bolt holes are precision drilled and the bolts epoxyed prior to installation.When the engines are bolted in they become a semi-stressed member much like a racing car engine into it's chassis thereby equalising the load between all the mounting points.To achieve this you have to work to much greater accuracy so you don't pre stress the mountings statically.In the original revenger build they may have chosen to spread the load over a very large area because they built a light structure as you have now considerably reinforced the hull this may not be necessary.

Regards

Peter

peterunwin · 05-12-2010, 08:04 PM

Quote:

Originally Posted by baj666

another fine post mate

..watch your hair dont get caught up in the drill Peter

Thanks baj666,
I am only using a 1200 watt drill so i think my hair would probably stall it!!!

Regards

Peter

peterunwin · 05-12-2010, 08:52 PM

Quote:

Originally Posted by Tony Davis

Hey Pete, I'm curious as to the thinking behind the engine mounts, did you have second thoughts about going purely CF, or were they more for bling purposes and you'd planned to double them up with Ally?

Hi Tony,
The original plan was to use stainless steel spreader plates but these didn't look very nice so i decided to go with aluminium angles cut to the same size & shape as the carbon.The aluminium has three functions the first one is to provide a drilling jig secondly to spread the load evenly from the bolts into the carbon as i have previously found that without spreading the load you lose the bolt tension over a long period of time and thirdly they look quite nice. Structurally the carbon on it's own would be more than up to the job.

Regards

Peter

Captain Chaos · 05-12-2010, 10:26 PM

That sounds fair enough Peter. On the the 3rd point alone, I'd say terrific job, they look really nice.

BBCMI · 06-12-2010, 01:37 PM

Quote:

Originally Posted by peterunwin

Hi All,
I bonded in all the aluminium backings into the carbon engine mounting angles, after the bonding is cured i can drill the mounting holes through the pre-drilled aluminium. Also made up all the pipework for the fuel tank fillers,I have used 2" thin wall aluminium tube with preformed 90 degree and 45 degree rubber elbows for a lightweight and compact installion.

Peter

Peter,
A very impressive project! I sent you a couple of PM's, check your in box.
Chris

baj666 · 06-12-2010, 05:02 PM

ile tell you what...if i ever came into big money then this man would be my 1st choice for biulding my dream boat from the hull up as the attention to detail is unreal

peterunwin · 10-12-2010, 05:21 PM

Hi All,
It's been another busy week coating the engine bay with epoxy paint, it is going to require 3 coats to get the desired finish, being wise after the event i would have had the middle coat tinted a slightly different colour as it is extremely difficult to see where you have been when overcoating with the same colour but hopefully worth it in the end, also installed the fuel tank fillers although it is a single tank i have a port and starboard filler, now just the breather to connect and the tank installation is finished

The weather has been pretty cold up in the Midlands which has slowed down the curing process so i haven't been able to do so much in the engine bay as i would have liked

hopefully warming up a bit next week!!

Regards

Peter

Tony Davis · 10-12-2010, 06:14 PM

Single jubilee's on the fuel delivery???

peterunwin · 11-12-2010, 11:03 AM

Quote:

Originally Posted by Tony Davis

Single jubilee's on the fuel delivery???

Hi Tony,
I will have to put on my hydraulic engineering cap on to answer this one. Having operated a hydraulic design and repair facility for well over 30 years i am always highly suspicious of installations with doubled up hose clips, as in my experience this usually means the hose selected is too large for the hose tail or pipe it is being fitted to and two clips or more are fitted to provide a seal.
As you can probably imagine i have at my disposal numerous engineering solutions that i could have used but not being a man to over engineer, the single high torque hose clip was selected which has extremely good integrity provided that the hose is a good tight fit on the hose tails, the hose clips chosen are of the correct diameter for the pipe. The hose clips chosen at 50% of their max tightening torque which already has a safety factor built in were tested to 20psi prior to installation.As the tank is atmospheric the only pressure they will have to deal with is fuel surge, there will also be a bracket on the side of the hull supporting the alloy tube.

Regards

Peter

Tony Davis · 11-12-2010, 12:58 PM

I always fit 2 on fuel lines, probably because that's what's expected by most customers. I'm not sure if it's a requirement for CE purposes, but it certainly can't do any harm.

peterunwin · 14-12-2010, 08:17 PM

Hi All,
The thin wall tube arrived today for the exhaust tailpipes so i set to making a pair of swaging dolly's out of some scrap brass cylinder glands. The outer tube swage connects up to the flange on the headers the inner tube swage sits inside the bore of the outer tube so the inner can be welded to the outer.

Regards

Peter

peterunwin · 15-12-2010, 09:17 PM

Hi All,
I carefully marked and ground out the water passages for the inner tailpipes, these have been carefully arranged to form a weir system so that jacketed section of pipe remains full of water even at idle speed. The slots have been carefully calculated to match the water pump output at full rpm, they also drain totally when the engines are not running.

Peter

larby · 15-12-2010, 10:28 PM

Nicely done

If everyone who worked in a mechanical position was like you, I don't think breakdowns would exist!

James

peterunwin · 19-12-2010, 10:26 AM

Quote:

Originally Posted by larby

Nicely done

If everyone who worked in a mechanical position was like you, I don't think breakdowns would exist!

James

Hi James,
It' always nice to receive a compliment about your work. I have spent all of my life designing and making components, i get lot's of satisfaction out of making things that are unique and it's a lot cheaper than paying someone else to do it.

Thanks
Peter

peterunwin · 19-12-2010, 10:46 AM

Hi All,
Made up some lightweight T handles for the strainer stopcocks, these replace the original L handles which fouled on the engine bearers also made the angles to support the fuel delivery pipes.

Peter

larby · 19-12-2010, 12:10 PM

Quote:

Originally Posted by peterunwin

Hi James,
It' always nice to receive a compliment about your work. I have spent all of my life designing and making components, i get lot's of satisfaction out of making things that are unique and it's a lot cheaper than paying someone else to do it.

Thanks
Peter

I know what you mean! I started off working in mechanical engineering, mainly in R&D, and I'm a complete perfectionist when I'm able. I really miss being able to machine parts myself and having to make do with the limited tools I've got, not to mention a greatly restricting budget, it's very frustrating!
Still, at least I'm getting plenty of pratice in with my current projects, plan is that the next one will be based on a new hull, built while I've still got the revenger so I don't rush!

Watching your build is a true inspiration and it's amazing to see someone going to such incredible lengths to make a boat just right. I've seen it before with people building cars, albeit not to this level, but never on a boat before. There's not one item used because 'it'll do', not a single comprimise. It's either perfect, or it's changed until it is.
Keep up the good work, I can't wait to see it in the flesh some time, you'd better have it done in time for the Guernsey Powerboat week next year!!

Cheers, James

peterunwin · 21-12-2010, 07:40 PM

Hi All,
Mounted the water pickups permanently, i used tigerseal on the outside, allowed this to cure for 24hrs and then filled the internal cavity with epoxy. I had previously made a spigot and socket joint which was also liberally dosed with epoxy and then pushed into the transom from the inside, a little bit messy but it ain't coming out, also with the same batch of epoxy managed to fit all the engine mounting bolts. I then moved on to the bilge pumps manual and electric, all the pipe work is being deliberately undersized and i have used a heat gun to soften the hose and enable me to push it on to the hosetails this saves both the weight and cost of hose clips, the downside is if you ever want to remove them you will have to cut them off but i think the benefit out ways the inconvenience.

Peter

peterunwin · 23-12-2010, 05:52 PM

Hi All,
Got lot's done over the last couple of days

Started mounting all the rigging parts permanently, water strainers went in first followed by their associated pipework. I have used a sealant on all the stainless steel threads not required for sealing purposes but it does prevent the stainless steel threads from galling. I then moved on to the trim pumps, i have used stainless steel countersunk screws with cup washers, again i have applied sealant to all the screws, finally moved on to the batteries which are mounted using a mixture of stainless and aluminium angles which are bent to suit the angle of the V.

Peter